CN104570661A - Developing device - Google Patents

Abstract

An object of the present invention is to provide a developing device capable of suppressing developer leakage. The developing device (developing cartridge (28)) includes a frame (50) that accommodates the developer inside, a developing roller (31) that is rotatably installed in the frame and carries the developer on its surface, and a layer thickness limiter that contacts the developing roller. A doctor blade (100) and a seal member (side seal (200)) arranged between the frame and both ends in the axial direction of the developing roller. The layer thickness regulating blade has a blade body (110) extending in the axial direction and a blade rubber portion (120) protruding from a surface of the blade body opposite to the developing roller and in contact with the developing roller. An axial end surface (120A) of the scraper rubber part is in contact with an axially inner end surface (221) of the seal member. A suppressing portion (first protruding portion ( 211 )) for suppressing the tendency of the developer to flow is provided at a corner portion between the blade rubber portion and the sealing member.

Description

developing device

technical field

The present invention relates to a developing device including a developing roller and a layer thickness regulating blade.

Background technique

Conventionally, a developing device used in an image forming apparatus has a frame housing a developer, a developing roller rotatably held by the frame, a layer thickness regulating blade in contact with the developing roller, and a blade disposed between the frame and the developing roller. The structure of the sealing member between them (for example, refer to Patent Document 1). In this developing device, the layer thickness regulating blade has a blade main body made of sheet metal, and a blade rubber portion that protrudes from the blade main body and contacts the developing roller.

The sealing member is provided in a shape matching the outer peripheral surface of the developing roller, and one end is attached to both ends of the blade main body. And, the end surface of the seal member on the axially inner side of the developing roller is in contact with the end surface of the blade rubber portion on the axially outer side of the developing roller.

prior art literature

patent documents

Patent Document 1 JP-A-2010-164736

However, in the above technique, there are cases where the developer scraped off by the end of the blade rubber part strongly flows toward the seal member side due to the shape of the blade rubber part, and sometimes the developer cannot be completely blocked by the seal member and leaks to the seal member. external.

Contents of the invention

Therefore, an object of the present invention is to provide a developing device capable of suppressing leakage of developer.

In order to solve the above-mentioned problems, a developing device according to the present invention includes: a frame housing a developer therein; a developing roller rotatably provided in the frame and carrying the developer on its surface; a layer thickness regulating blade and the a developing roller contact; and a sealing member arranged between the frame and both ends in the axial direction of the developing roller. The layer thickness regulating blade has a blade main body extending in the axial direction and a blade rubber portion protruding from a surface of the blade main body opposed to the developing roller and in contact with the developing roller. The axial end surface of the blade rubber portion is in contact with the axially inner end surface of the seal member. A suppressing portion for suppressing a tendency of the developer to flow is provided at a corner portion between the blade rubber portion and the sealing member.

According to this configuration, when the developer scraped off by the end of the blade rubber part tends to move strongly toward the sealing member, the suppressing portion suppresses this tendency, so it is possible to suppress the tendency of the developer to forcibly flow into the sealing member. situation, so that leakage of the developer can be suppressed.

In addition, in the above configuration, the sealing member may include a contact member that contacts the developing roller, and an elastic member disposed between the contact member and the frame, and the elastic member There is a first protruding portion protruding further inward in the axial direction than the contact member, an end surface in the axial direction of the blade rubber portion contacts an end surface in the axial direction of the contact member, and the The first protruding portion is arranged at a corner between the blade rubber portion and the contact member, and the first protruding portion functions as the suppressing portion.

Thus, since a part of the elastic member is used as the suppressing portion, the number of parts can be reduced compared to, for example, a configuration in which the suppressing portion is configured by a member different from conventional members such as elastic members.

In addition, in the above configuration, the seal member may have a contact member that contacts the developing roller and an elastic member disposed between the contact member and the frame, and the blade main body An extension portion extending to a position upstream in the rotation direction of the developing roller from an end portion of the blade rubber portion in the axial direction, the end surface of the blade rubber portion in the axial direction and The axially inner end surface of the contact member contacts, and the extension portion functions as the suppressing portion by disposing the extension portion at a corner portion between the blade rubber portion and the contact member.

Thereby, a part of the spatula main body is used as the suppressing portion, and therefore, the number of parts can be reduced compared to, for example, a structure in which the suppressing portion is configured by a member different from conventional parts such as the spatula main body.

In addition, in the above configuration, the elastic member may have a second protruding portion, the second protruding portion is arranged on the upstream side of the suppressing portion in the rotation direction of the developing roller, and the second protruding portion The protruding portion protrudes further inward in the axial direction than the suppressing portion.

Thereby, since the developer can be suppressed from moving to the corner between the blade rubber portion and the contact member by the second protruding portion, it is possible to further suppress the strong flow of the developer into the sealing member.

In addition, in the above configuration, the elastic member may have a third protrusion disposed on the upstream side of the second protrusion in the rotation direction of the developing roller, and the third protrusion may The third protrusion protrudes further inward in the axial direction than the second protrusion.

Thereby, since the developer can be suppressed from moving to the corner between the blade rubber portion and the contact member by the third protrusion, it is possible to further suppress a strong flow of the developer into the sealing member.

In addition, in the aforementioned structure, the length of the restraining portion in the axial direction is within a range of 0.5 mm to 3 mm.

In addition, in the above-mentioned structure, the blade rubber portion may extend toward the upstream side in the rotation direction of the developing roller at both ends in the axial direction as it goes outward in the axial direction. to the inclined face of the sealing member.

As a result, the developer scraped off by the inclined surface of the blade rubber portion moves toward the inner side of the developing roller in the axial direction, that is, the side opposite to the sealing member by moving along the inclined surface. As a result, the developer scraped off by the inclined surface does not flow into the sealing member forcefully, so that leakage of the developer can be suppressed.

In addition, in the above configuration, the inclined surface may be provided within a range where the blade rubber portion contacts the developing roller.

Thereby, since the entire inclined surface contacts the developing roller, it is possible to suppress abrasion of only a part of the inclined surface.

According to the present invention, leakage of the developer can be suppressed.

Description of drawings

FIG. 1 is a cross-sectional view showing a schematic configuration of a laser printer including a developer cartridge according to an embodiment of the present invention.

Figure 2 is a sectional view of the process cartridge.

3 is an enlarged perspective view showing the structure around the opening of the developing cartridge.

Fig. 4 is a cross-sectional view of the developing cartridge taken along a plane passing through side seals and perpendicular to the axial direction of the developing roller.

Fig. 5 is a view showing the end portion of the layer thickness regulating blade and a side seal body, and is a diagram (a) showing a state where a contact member etc. is detached from a base material, etc. The figure (b) of the state and the figure (c) which show the form which does not have a 1st protrusion part.

6 is a view showing a developing roller and a layer thickness regulating blade, and is a cross-sectional view (a) of a central portion in the left-right direction and a cross-sectional view (b) of a cutout portion.

7 is a view showing the end of the layer thickness regulating blade and the side sealing body in Modification 1, and is a diagram (a) showing a state where the contact member and the like are detached from the base material, etc. Figure (b) of the state after pasting on a base material, etc.

Fig. 8 is a view showing the end of the layer thickness regulating blade and a side seal body in modification 2, and is a diagram (a) showing a state where a contact member etc. is detached from a base material, etc. Figure (b) of the state after the member etc. are pasted on the base material etc.

Detailed ways

Next, an embodiment of the present invention will be described in detail with appropriate reference to the drawings. In addition, in the following description, first, the overall structure of the laser printer will be briefly described, and then the details of the characteristic parts of the present invention will be described.

In addition, in the following description, description will be made based on the direction of the user when using the laser printer 1 . That is, the left side in FIG. 1 is "front", the right side is "rear", the back side is "left", and the front side is "right". In addition, the up-down direction in FIG. 1 is "up and down".

＜Overall structure of laser printer＞

As shown in FIG. 1 , the laser printer 1 includes a paper feeding unit 4 for feeding paper 3 into a main body casing 2 , an image forming unit 5 for forming an image on the paper 3 , and the like.

The paper feed unit 4 includes a paper feed tray 6 detachably attached to the bottom of the main body casing 2 , and a paper pressing plate 7 provided in the paper feed tray 6 . In addition, the paper feed unit 4 includes various rollers 11 for conveying the paper 3 and collecting paper dust. Further, in the paper feeding unit 4 , the paper 3 in the paper feeding tray 6 is moved upward by the paper pressing plate 7 and conveyed to the image forming unit 5 by various rollers 11 .

The image forming unit 5 includes a scanner unit 16 , a process cartridge 17 , a fixing unit 18 and the like.

The scanner unit 16 is provided in the upper part of the main body casing 2, and includes a laser light emitting unit (not shown), a rotationally driven polygon mirror 19, lenses 20, 21, mirrors 22, 23, 24, and the like. In this scanner unit 16 , the laser beam is irradiated on the surface of the photosensitive drum 27 by high-speed scanning through a path indicated by a dashed-dotted line in the figure.

The process cartridge 17 is detachably attached to the main body casing 2 by appropriately opening the front cover 2A provided on the near side of the main body casing 2 . Further, the process cartridge 17 is mainly composed of a developing cartridge 28 as an example of a developing device and a drum unit 39 .

The developer cartridge 28 can be attached to and detached from the main body casing 2 while being attached to the drum unit 39 . As shown in FIG. 2 , the developing cartridge 28 includes a developing roller 31 , a layer thickness regulating blade 100 , a feed roller 33 , and a frame body 50 that supports these members. In addition, the housing 50 has a toner storage chamber 34 that contains a toner as an example of a developer therein.

The layer thickness regulating blade 100 has a blade body 110 and a blade rubber part 120 fixed to the blade body 110 .

The scraper body 110 is a sheet metal extending in the left-right direction. The blade main body 110 is fixed to the frame body 50 above the developing roller 31 , and its front end is disposed in front of the developing roller 31 .

As shown in FIG. 3 , the scraper rubber part 120 is a rubber member that is elongated in the left-right direction and smaller in the left-right direction than the scraper body 110 , and is formed of, for example, silicon rubber or urethane rubber. The blade rubber portion 120 protrudes from the surface facing the developing roller 31 at the front end portion of the blade main body 110 and is in contact with the developing roller 31 . The surface of the blade rubber portion 120 in contact with the developing roller 31 is planar, and the corners on the upstream and downstream sides in the rotational direction of the developing roller 31 are arcuate in cross-sectional view (see FIG. 6( a )). .

Returning to FIG. 2, in the developing cartridge 28, the toner contained in the toner containing chamber 34 is agitated by the agitator 34A, and then supplied to the developing roller 31 by the supply roller 33. and the developing roller 31 are frictionally charged. The toner carried on the outer peripheral surface of the developing roller 31 enters between the layer thickness regulating blade 100 and the developing roller 31 as the developing roller 31 rotates, is further frictionally charged, and is carried on the developing roller as a thin layer of a certain thickness. 31 on.

The drum unit 39 includes a photosensitive drum 27 , a grid-equipped scorotron charger 29 , and a transfer roller 30 . Then, in the drum unit 39 , the surface of the photosensitive drum 27 is similarly positively charged by the grid-equipped corona charger 29 , and then exposed by high-speed scanning with a laser beam from the scanner unit 16 . Thereby, the potential of the exposed portion is lowered, and an electrostatic latent image based on the image data is formed.

Next, the toner carried on the developing roller 31 is supplied to the electrostatic latent image formed on the surface of the photosensitive drum 27 by the rotation of the developing roller 31 , forming a toner image on the surface of the photosensitive drum 27 . Thereafter, the toner image carried on the surface of the photosensitive drum 27 is transferred onto the paper 3 by conveying the paper 3 between the photosensitive drum 27 and the transfer roller 30 .

As shown in FIG. 1 , the fixing unit 18 includes a heating roller 41 and a pressure roller 42 that is arranged to face the heating roller 41 and pressurizes the heating roller 41 . Further, in the fixing unit 18 configured as described above, the toner transferred onto the paper 3 is thermally fixed while the paper 3 passes between the heat roller 41 and the pressure roller 42 . In addition, the paper 3 thermally fixed by the fixing unit 18 is conveyed to the paper discharge roller 45 arranged downstream of the fixing unit 18 , and is discharged from the paper discharge roller 45 onto the paper discharge tray 46 .

<Detailed structure of the developing cartridge>

Next, the structure of the developing cartridge 28 will be described in detail. In addition, FIG. 3 shows a state in which the developing roller 31 is detached from the frame body 50 . In addition, since the structure around the opening 51 of the developing cartridge 28 is substantially the same at the left end and the right end, only the left end is shown in the drawings referred to in the following description.

As shown in FIG. 3 , the frame body 50 of the developing cartridge 28 has an opening 51 on the rear side wall, and the developing roller 31 is rotatably supported by the frame body 50 in a shape closing the opening 51 . The diaphragm 35 is provided at the lower edge of the opening 51 , and side seals 200 as an example of sealing members are provided at the left and right edges of the opening 51 . In addition, on the upper edge of the opening 51, the layer thickness regulating blade 100 is provided so as to extend in the left-right direction.

The side seals 200 are arranged between the frame body 50 and both ends in the axial direction, that is, in the left and right directions, of the developing roller 31 in a shape matching the outer peripheral shape of the developing roller 31 , and are in contact with the developing roller 31 . In addition, the diaphragm 35 is a sheet-shaped member extending in the left-right direction, and is in contact with the lower portion of the developing roller 31 . The blade rubber portion 120 of the layer thickness regulating blade 100 is in contact with the developing roller 31 from obliquely front and upward (see FIG. 2 ). In this way, in order to prevent the toner in the housing 50 from leaking around the developing roller 31, the developing roller 31 is in close contact with the layer thickness regulating blade 100, the diaphragm 35, and the side seal 200 in four directions: up, down, left, and right. In addition, in this embodiment, the developing roller 31 is provided so as to rotate in the direction of the arrow shown in FIG. 3 , that is, in the direction in which the peripheral surface slides upward on the surface of the side seal body 200 from bottom to top.

As shown in FIGS. 3 and 4 , the side seal body 200 has a base material 210 attached to the frame body 50 , and a contact member 220 that overlaps the base material 210 and contacts the developing roller 31 .

The base material 210 is, for example, an elastic member formed of polyurethane sponge. The lower end of the substrate 210 is arranged below the developing roller 31, and the upper end is arranged on the back side (front side) of the blade body 110 of the layer thickness regulating blade 100, and contacts the blade body 110 from the side opposite to the developing roller 31. The base material 210 is attached to the frame body 50 with double-sided tape or the like.

In addition, on the surface side (rear side) of the blade main body 110 , blade-side sealing bodies 130 made of urethane sponge or the like are attached adjacent to both sides in the left-right direction of the blade rubber portion 120 .

The contact member 220 is, for example, a substantially rectangular member formed of a fiber member such as a nonwoven fabric or a woven fabric member. The contact member 220 extends from a position overlapping with the scraper side sealing body 130 to the rear side of the lower end of the base material 210, and is pasted on the scraper side sealing body 130, the base material 210, and the portion extending to the base material 210 by double-sided tape or the like. A part of the frame body 50 whose lower end is closer to the rear. Further, the upper end of the contact member 220 is provided above the contact portion TP (see FIG. 6( b )) between the blade rubber portion 120 and the developing roller 31 . In addition, the material of the contact member 220 may be pile fabric, felt, or Dyneema (manufactured by Toyobo Co., Ltd.). Moreover, when using the fiber of a pile fabric and a Dyneema fiber, it is preferable to weave in the inclined shape which goes inward in the left-right direction as it goes upward. In addition, it is preferable that the inclination angle is substantially equal to the angle of the inclination surface 122 (see FIG. 8 ) described later with respect to the developing roller axis.

As shown in FIGS. 5( a ) and ( b ), the lateral end surface 120A of the blade rubber portion 120 of the layer thickness regulating blade 100 is in contact with the laterally inner end surface 221 of the contact member 220 . Further, the scraper rubber portion 120 is provided with notches 121 formed in a shape dented upward at both end portions in the left-right direction. In addition, the front end of the scraper main body 110 is formed in a shape corresponding to the scraper rubber part 120 , and both ends 111 in the left and right directions extend to the outside of the scraper rubber part 120 . Specifically, lower end portions 111A of both end portions 111 of the blade main body 110 extend below (upstream in the rotational direction of the developing roller 31 ) than both end portions (first side surfaces 123 described later) of the blade rubber portion 120 .

Here, the vertical length of the end surface 120A of the scraper rubber part 120 may be, for example, 3 mm, and the lateral width of both ends 111 of the scraper body 110 may be, for example, 7 mm. In addition, the present invention is not limited thereto, and the length in the vertical direction of the end surface 120A of the blade rubber portion 120 may be, for example, 2.5 to 4 mm. In addition, the width in the left-right direction of both ends 111 of the scraper body 110 may be, for example, 6 to 8 mm.

The slit 121 is formed to have a first side surface 123 extending from the lower end of the end surface 120A inward in the left-right direction in the axial direction of the developing roller 31 and a second side surface 124 extending downward from the first side surface 123 . Here, the length of the first side 123 in the left-right direction may be, for example, 4 mm, and the length of the second side 124 in the up-down direction may be, for example, 1.5 mm. In addition, the present invention is not limited thereto, and the length of the first side 123 in the left-right direction may be, for example, 3-6 mm, preferably 3-4 mm. In addition, the length of the vertical direction of the second side surface 124 is sufficient as long as the lower end of the second side surface 124 is located outside the nip (contact portion) between the developing roller 31 and the blade rubber portion 120, for example, it may be 1 to 3 mm. .

By providing such slits 121 in the blade rubber portion 120 , the surface of the blade rubber portion 120 in contact with the developing roller 31 forms approximately right angles with the corners of the first side surface 123 and the second side surface 124 (see FIG. 6( b )).

And, as shown in FIG. 5( b ), as an example of a suppressing portion for suppressing the tendency of the toner to flow, a part of the substrate 210 is arranged at a corner between the blade rubber portion 120 and the contact member 220 . . Specifically, base material 210 has first protruding portion 211 , second protruding portion 212 , and third protruding portion 213 protruding inward in the left-right direction relative to contact member 220 in a state where contact member 220 is attached.

The layer thickness regulating blade 100 is arranged on the upper part 211A of the first protruding part 211 so as to overlap from the surface side, and the lower end part 211B of the first protruding part 211 protrudes to the first position than the notch 121 of the blade rubber part 120 . The side surface 123 is disposed so as to be on the lower side. That is, the lower end portion 211B of the first protruding portion 211 is arranged at the corner between the blade rubber portion 120 and the contact member 220 , specifically, at the inner side in the left-right direction from the first side surface 123 of the notch 121 and the contact member 220 . The corner portion formed by the end surface 221 functions as the aforementioned suppressing portion.

Here, the length in the left-right direction of the first protruding portion 211 may be, for example, 1 mm. In addition, the present invention is not limited thereto, and the length in the left-right direction of the first protruding portion 211 may be, for example, 0.5-3 mm, preferably 0.5-3 mm, and more preferably 1-3 mm.

In addition, the length in the vertical direction of the lower end portion 211B of the first protruding portion 211 may be, for example, the same length (1.5 mm) as that of the second side surface 124 . In addition, the present invention is not limited thereto, and the length in the vertical direction of the lower end portion 211B of the first protruding portion 211 may be, for example, 1 to 3 mm.

In addition, when the developing roller 31 is attached to the frame body 50 while being pressed against the layer thickness regulating blade 100 and the side seal 200 , the first protruding portion 211 may or may not be in contact with the developing roller 31 .

The second protruding portion 212 is arranged adjacent to the first protruding portion 211 on the upstream side in the rotational direction of the developing roller 31 , and protrudes to the inside in the left-right direction of the first protruding portion 211 .

The third protruding portion 213 is arranged adjacent to the second protruding portion 212 on the upstream side in the rotational direction of the developing roller 31 , and protrudes inward in the left-right direction from the second protruding portion 212 .

In addition, the protrusion amount of the second protruding portion 212 relative to the first protruding portion 211 may be, for example, 0.5-2 mm, preferably 0.5-1 mm. In addition, the protrusion amount of the third protruding portion 213 relative to the second protruding portion 212 may be, for example, 0.5-2 mm, preferably 1-1.5 mm.

The action and effect of the developer cartridge 28 configured as described above will be described.

As shown in FIG. 6( a ), when the developing roller 31 rotates, the toner on the developing roller 31 is scraped off by the blade rubber portion 120 of the layer thickness regulating blade 100 .

At this time, the developing roller 31 is in contact with the flat surface of the blade rubber portion 120 in the portion on the inner side in the left-right direction than the notch 121 , whereas, as shown in FIG. 6( b ), in the portion of the notch 121 , The corner portion of the blade rubber portion 120 on the upstream side in the rotation direction of the developing roller 31 forms a substantially right angle, and the corner portion is in contact with the developing roller 31 . Accordingly, at the position corresponding to the notch 121 of the developing roller 31 , more toner can be scraped off than at the position inside the notch 121 in the left-right direction.

Accordingly, since the toner layer carried on the end portion of the developing roller 31 becomes thinner, toner leakage from the end portion of the developing roller 31 can be suppressed.

However, in the structure in which the scraper rubber part 120 is provided with the cutout 121, as shown in FIG. Sometimes a large amount of toner scraped by the cutout 121 moves outward in the left-right direction along the first side surface 123 and flows into the contact member 220 strongly. Also, if the toner flows into the contact member 220 strongly, there is a possibility that the contact member 220 cannot block the toner and the toner leaks.

In the present embodiment, as shown in FIG. This tendency is weakened by the first protruding portion 211 . As a result, a large amount of scraped toner does not forcefully flow into the contact member 220, so toner leakage can be suppressed.

In addition, in this embodiment, part of the base material 210 (the lower end portion 211B of the first protruding portion 211 ) functions as a suppressing portion for suppressing the tendency of the toner to flow. The number of parts can be reduced compared with the conventional structure in which the suppressing part is formed by members with different parts.

In addition, by providing the second protrusion 212 protruding inward in the left-right direction relative to the first protrusion 211 on the upstream side of the rotation direction of the first protrusion 211 , the second protrusion 212 can suppress the transfer of toner to the blade rubber 120 . Since the corner between the contact member 220 and the contact member 220 moves, it is possible to further suppress the toner from flowing strongly into the contact member 220 .

In addition, by providing the third protrusion 213 protruding inward in the left-right direction relative to the second protrusion 212 on the upstream side of the rotation direction of the second protrusion 212 , the third protrusion 213 can suppress the toner from moving toward the blade rubber 120 . Since the corner between the contact member 220 and the contact member 220 moves, it is possible to further suppress the toner from flowing into the contact member 220 strongly.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. About a specific structure, it can change suitably in the range which does not deviate from the summary of this invention. In addition, in the following description, the same code|symbol is attached|subjected to the structural element substantially the same as the said embodiment, and the description is abbreviate|omitted.

In the above-mentioned embodiment, a part of the base material 210 is made to function as a suppressing part, but the present invention is not limited thereto, for example, as shown in Fig. 7 (a), (b), a part of the scraper body 110 may be Functions as a suppressor. Specifically, in this embodiment, the inner portion A1 extending to the inner side in the left-right direction of the lower end portion 111A of the both end portions 111 of the scraper main body 110 than the first side surface 123 of the scraper rubber portion 120 is used as a restraining portion. function.

Specifically, the inner portion A1 is an example of an extension portion, which extends to the lower side than the first side surface 123 of the blade rubber portion 120 and extends to the left-right inner side than the end surface 221 of the contact member 220, and is disposed on the blade rubber portion. 120 and the corner between the contact member 220.

Even in the case where the inner portion A1 of the blade main body 110 is disposed at the corner between the blade rubber portion 120 and the contact member 220 as described above, the inner portion A1 can be used to push the toner along the second edge of the blade rubber portion 120 . The tendency of the one side surface 123 to flow outward in the left-right direction is weakened, so toner leakage can be suppressed. In addition, since part of the spatula main body 110 (inner portion A1) functions as the suppressing portion, the number of parts can be reduced compared to a configuration in which the suppressing portion is constituted by a member different from a conventional spatula body, for example.

In the above embodiment, the first side surface 123 is formed to extend linearly from the second side surface 124 to the end surface 221 of the contact member 220, but the present invention is not limited thereto. As shown in b), the inclined surface 122 is provided between the first side surface 123 and the end surface 221 of the contact member 220 .

Specifically, in this form, the first side surface 123 extends from the second side surface 124 to the inner surface of the first protruding portion 211 in the left-right direction. In addition, the inclined surfaces 122 are provided at both ends of the blade rubber portion 120 in the left-right direction, and are directed toward the upstream side in the rotation direction of the developing roller 31 from the left-right outer end edge of the first side surface 123 toward the left-right outer side, and Extends to the end face 221 of the contact member 220 .

Accordingly, the toner scraped by the inclined surface 122 of the scraper rubber portion 120 moves inward in the left-right direction, that is, on the side opposite to the side seal body 200 , by moving along the inclined surface 122 . As a result, the toner scraped by the inclined surface 122 does not forcefully flow into the side seal body 200 , so toner leakage can be further suppressed.

In addition, the inclined surface 122 may be provided in a range where the blade rubber portion 120 is in contact with the developing roller 31 (the range of cross-hatching delineated by a two-dot chain line and hatched in the figure). Thus, the entire inclined surface 122 is in contact with the developing roller 31 , so that only a part of the inclined surface 122 can be suppressed from being worn.

In addition, the angle of the inclined surface 122 with respect to the axial direction of the developing roller 31 may be, for example, 30° to 60°. In addition, the width of the inclined surface 122 in the left-right direction may be, for example, 0.5-3 mm, preferably 1-3 mm.

In the above-mentioned embodiments, the sealing member is composed of the contact member and the base material (elastic member), that is, two layers, but the present invention is not limited thereto. For example, the sealing member may be composed of one layer, or may be composed of three or more layers. .

In the above-described embodiment, the present invention is applied to the developing cartridge 28 included in the laser printer 1 , but the present invention can also be applied to developing devices included in other image forming apparatuses such as copiers and multifunction machines.

In the above-described embodiments, the present invention is applied to the developing cartridge 28, but the present invention is not limited thereto. For example, the present invention can also be applied to other developing devices such as a process cartridge in which a developing cartridge and a drum unit are integrally formed, and a developing device in which toner is supplied from a toner cartridge containing toner.

Claims (8)

1. A developing device, characterized in that, It includes: a frame body, which accommodates the developer inside; a developing roller, which is rotatably arranged on the frame, and carries a developer on the surface; a layer thickness limiting blade in contact with the developing roller; and a sealing member disposed between the frame body and both ends in the axial direction of the developing roller, The layer thickness regulating blade has a blade body extending in the axial direction and a blade rubber portion protruding from a surface of the blade body opposite to the developing roller and in contact with the developing roller, The axial end surface of the scraper rubber portion is in contact with the axially inner end surface of the sealing member, A suppressing portion for suppressing a tendency of the developer to flow is provided at a corner portion between the blade rubber portion and the sealing member. 2. The developing device according to claim 1, wherein: The sealing member has a contact member in contact with the developing roller and an elastic member disposed between the contact member and the frame, the elastic member has a first protrusion protruding further inward in the axial direction than the contact member, the axial end surface of the blade rubber portion is in contact with the axially inner end surface of the contact member, By arranging the first protruding portion at a corner between the blade rubber portion and the contact member, the first protruding portion functions as the suppressing portion. 3. The developing device according to claim 1, wherein: The sealing member has a contact member in contact with the developing roller and an elastic member disposed between the contact member and the frame, The blade main body has an extension portion extending to a position upstream in the rotation direction of the developing roller from an end portion of the blade rubber portion in the axial direction, the axial end surface of the blade rubber portion is in contact with the axially inner end surface of the contact member, By arranging the extension portion at a corner between the blade rubber portion and the contact member, the extension portion functions as the suppressing portion. 4. The developing device according to claim 2 or 3, wherein: The elastic member has a second protruding portion disposed on the upstream side in the rotation direction of the developing roller than the suppressing portion, and the second protruding portion is further in the axial direction than the suppressing portion. Prominent on the inside. 5. The developing device according to claim 4, wherein: The elastic member has a third protruding portion disposed on an upstream side of the second protruding portion in a rotational direction of the developing roller, and the third protruding portion is further toward the developing roller than the second protruding portion. The shaft protrudes inwardly. 6. The developing device according to any one of claims 1-3, characterized in that, The length of the restraining portion in the axial direction is within a range of 0.5 mm to 3 mm. 7. The developing device according to any one of claims 1-3, wherein: The blade rubber portion has inclined surfaces extending toward the sealing member toward the upstream side in the rotational direction of the developing roller as they go outward in the axial direction at both end portions in the axial direction. 8. The developing device according to claim 7, wherein: The inclined surface is provided within a range where the blade rubber portion contacts the developing roller.